Hollow sheet-metal unit and process of producing the same



A. R. G ROSS Dec. 31, 1929.

HOLLOW SHEET METAL UNIT AND PROCESS OF PRODUCING THE SAME Filed Sept. 15, 1927 2 Sheets-Sheet' l Dec. 31, 1929. A. R. GROSS 1,

' HOLLOW SHEET METAL UNIT AND PROCESS OF PRODUCING THE SAME Filed Sept. 15, 1927 sneets-sneet 2 MYJQE: xv f; if 2;? U

Q m J Patented Dec. 51, 1529 ITEDj-SrAT S PATENT OFFICE ARTHUR n. GROSS, or s'r. m 1.

DEL AWARE ia oriiiow SHEET-METAL UNIT AND [I Application filed September present invention relates to a holldw sheet metal unit having an internal reinforcement secured thereto by spot welding, and

the processof producing the same, and has I for its object to provide such a unit that is of relatively light weight, strong and rigid and has the joints between its sections and between the unit and the reinforcementfill'ed 9 to deaden sound thus eliminating metallic rm 7 'fhe invention, while intended for general use in the construction of table tops and panels in building structures, car bodiesand the like, is especially well adapted in tlie con- 5 struction of doorsand is so illustrated and described in the present application.

' To the above end, generally stated, the inventionconsists of the novel devices and com,

definedintheclaiin- In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the, several views.

Referring to the drawin s:

Fig. 1 is aview partly in side elevation and partly in vertical section, with some parts broken away, illustratingthe improved door, and an apparatus for carrying out the improved process; l g

Fig. 2 is a fragmentary view partly in side elevation and partly in section showing one en%of the door and the attached han er bar ig. 3 is an end view with some parts sectioned'on the line 3-3 of Fig.2;

Fig. 4 is a fragmentary perspective view showing one corner of thedoorg Fig. 5 is a fragmentary detail View principally in section taken"on the-line of binations of devices hereinafter described and Fig. 2; m

Figl 6 isfa perspective view of one of the T-bolts; a'

- Fig. 7 is a perspective view of one of the spacing blocks; v Fig. 8 is a view in section taken longitudinally through a. section of the door and illustrating the coating material applied there to; and v Fig. 9. is a transverse section taken onthe line 99 of Fig. 8. u

The numeral 10md1catesa hollow sheet MINNESOTA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO .TRUSSBILT STEEL DOORS, INC., 015 ST. PAUL, MINNESOTA, A CORPORATION OF- I'ROCESS OF PRODUCING THE SAME 15,1927. Serial No. 219,642.

ends of the door 10- are closed by channel end I pieces 14 fitted therein with their flanges turned outward and spot welded at 15 to the plates 11. Longitudinal slots 16 are formed in each end of each end piece 14, to afford liquid filling and drain holes, for a purpose that will presently appear.

Within the door 10 is a truss structure 17* for the plates 11 and comprises ,a corrugated sheet metal plate. The apexes of the corrugations in the truss structure 17 are flat, alternately and directly engage the inner faces of it e platell andare spot welded thereto a The longitudinal edges of the truss structure" 17 are shaped to form portions of the joint-$ 12 and which joints are preferably of the type disclosed and broadly claimed in my co-pending application entitled Metal door structure, filed June 13, 1927, under Serial No. 198,488. It is important to note that the truss structure 17 terminates short of the end 'pieces'14 and thus leaves a shallow chamber 19 in each e d of the door with which the respective en s of the tubular sections in the truss structure 17 formed by the corrugations therein have communication and into which 0 chambers the slots 16 open.

The apparatusused in treating thedoor 10 to coat the same with a paint or other liquid coating material consists of a relatively deep and narrow tank 20, the top of which is substantially flush with the floor 21 and which tank contains a paint or other coating material :21. An overhead track 22 is securedto suitable supports not shown, and extends transversely over the tank 20; A carriage 23 is mounted on the track 22 and has a block and tackle 24 mounted thereon and including ahook 25. Removably attached to thehook 25 is a beam 26 having at its intermediate,

portion an eye 27 located slightly off center so as to hold said beam inclined, as shown in 'FigI 1. A pair of hooks 28 are flexibly attached one to each end of the beam 26 by short rods 29.

For obliquely suspending the door from the beam 26 by the hooks 28 edgewise in a horizontal position there is provided a pair of channel hanger bars 30 detachably secured to the ends of .the door 10 by pairs of nut equipped T-bolts 31 which extend through longitudinal slots 32 in the webs of said bars and through holes in the "webs of channel spacing blocks 33. The webs of the spacing blocks 33 bear against the websof the bars 30, and the flanges of said blocks 33 bear against the webs of the end piece 14 as bases of resistance. These spacing blocks 33 hold the bars 30 in the plane of the door 10 and slightly spaced from the ends thereof.

The heads of the T-bolts 31 are adapted to be inserted through the slots 16 and turned,

as shown by broken lines in Fig. 3, to span said slots and engage the inner faces of the end pieces 14 to secure said bolts to the door 10. The length of the heads of the bolts 31 is such that they cannot turn completely around in the compartments 19 and thereby engage the plates 11 and hold the bolts 31 from turning when operating the nuts thereon. .It is important to note that the bars are somewhat longer than the width 30 of the door 10 so that their lower ends serve as legs and their upper ends engage a wall or other support to hold said door in an inclined v position out of contact with any supporting member after the same has been dipped in the 35 coating-material w so that said material may dry without being touched.

In the ends of certain of the flanges of the channel hanger bars 30 are holes 34 through the upper of which the hooks 28 may be in- 404 serted to hold the door 10 suspended, as shown in Fig. 1. Vith the door thus suspended, the same. may be lowered into the tank 20 and submerged in the liquid material :0. lVhile the door 10 is submerged in the liquid material w, said materialwill enter the hollow door through the lowermost slots 16 and the air in said door will escape through the slot 16 in the uppermost corner of the door.

munication between all of the tubular sections in the truss structure v17, the material a:, upon entering said compartments, will completely fill the entire truss structure and coat the entire interior of the door 10. Capillary attraction will draw the material a: into all m of the joints between the different sections of the door 10 and the joints between the truss structure 17 and the door. It will be noted, by reference to Fig. 3, that the bolts 31 and spacing blocks 33 do not interfere with the passage of the material through the slots 16 and that said material. covers the entire door 10with the exception of very small areas covered by the heads of the bolts 31 and the flanges'of the spacing blocks 33.

As the compartments 19 afford com-- After the door 10 has been submerged in the material a: and left a sufiicient length of time for the material an to completely cover the same and enter all of the joints in the door and the truss structure, the door 10 is lifted from the tank 20 and held suspended to allow the surplus material a: to drain back into the tank 20 through the slot 16 in: the lower corner thereof. The inclined position in which the door 10 is held during the draining thereof prevents the accumulation of a surplus of said material on any spot or parts of the door 1.0. After the surplus material has been drained from the door 10, the same is handled by means of the bars 30 while detaching the hooks 28 from said bars and placed in position to dry, and during this time the bars 30 hold the door 1Q out of contact with any support or object so that the finishthereon is not marred by being touched. After the coating material on the door 10 is dry,.the exterior thereof may be finished with any suitable paint, enamel, or other surfacing material and then said finish baked thereon, in any well known manner. This dipping of the door. as previously stated,

completely fills" all joints between the different sections of the door and its truss structure and when dry the complete door unit is substantially an integral structure, thus preventing vibration deadening sound and thus eliminating metallic ring. The external coating material on the door 10 is indicated by y and the internal coating material on said door is indicated by 2, as shown in Figs. 8 and 9. Fig. 8 clearly illustrates, in an exaggerated manner, how the joints between the truss structure 17 and the plates 11, where they are connected by the spot welding 18, are filled by the material.

Vhat I claim is:

A hollow sheet metal unit having open ends, end members fitted in the open ends of the unit and closing the same, said end members having ventand drain holes, and an internal reinforcing member within the unit and transversely dividing the same into a plurality of longitudinally extended hollow scctions.'lu1\'ing open ends, said reinforcing; member terminating short of the end mem bers to' leave a chamber between each end member and the reinforcing member, the open ended hollow sections affording communication between the chambers. I

' In testimony whereof I ailix my signature.

ARTHUR R. GROSS. 

